Tunable, Q-switched Tm,Ho:LLF laser with a conductively cooled triangular prism rod.

We have developed a conductively cooled, Q-switched 2 µm laser with a triangular-prism Tm,Ho:LLF rod. Using a fused-silica acousto-optic Q-switch, the laser produced an output energy of 30 mJ in a single Q-switched pulse at a pulse repetition frequency of 5 Hz. Although the laser rod had polished lateral surfaces, no parasitic oscillation occurred, even at the maximum pumping level. In addition, broadly tunable laser performance was achieved with a birefringent filter plate under relatively large output coupling. The laser could be continuously tuned from 2051 to 2069 nm. Measured tuning characteristics were in reasonable agreement with calculated results.